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Evotrucker · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

What’s going folks!

So today while I was out doing a 70 mile run, after I stopped my coolant temp gauge started to climb. I was waiting n waiting for the fan to engage n it just kept climbing till it just stopped n didn’t go down till I started to drive. I was driving back to the yard empty with the container... here is a picture.

It was a hot one today, so while was working earlier in the evening, the temp climbed but I couldn’t hear or feel the fan kicking on. At one point or another, when the temp got to 210 i would just ease of the pedal n take it really easy n the temp would go down gradually.

The radiator is maybe a year old now, thermostat was replaced when I was rebuilding the motor last year....

I’m scratching my hair out trying to figure out what the issue is.

In all honesty my fan hub looks like it should have been replaced a long time ago! So the fan clutch could would be my prime suspect in this case.

Thanks again!

Waterloo · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

Fan clutch is my guess if it did not engage... I replaced mine at 950,000, it was still operational, but the motor was apart, and from what I could tell, it was the OEM original. Call it preventative maintenance. Odds are, if I am reading your mileage correctly, it would be a good idea to install a new one. But that is just me.

marek4792 · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

Had cm870 that would always run hot pretty much threw every part at it thermostats+seals water pump fan clutch radiator you name it oil cooler tstat, tuning was proper and ran perfectly but the son of a bitch would always hit 215 and the oil temp would peg 250 on a long pull. Only thing I didn't touch was the oil cooler core itself which I narrowed it down to but can't confirm as its probably a refrigerator in someones kitchen right about now..

Chamberpains · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

Where is your laptop with Insite and inline adapter. Please oh please don't tell me after all we've seen you do to this truck, and you don't have Insite?

If you do, go to data monitor\logger and check your fan control switch. Is it being commanded on? In ECM Diagnostic Tests you can perform a switch test. Toggle your fan on and off to see if its engaging or leaking air.
Your problem may just be the solenoid isn't allowing it to come on or your clutch in the hub is shot. Does it engage when you turn the key off and disengage when you key on?

Lonestar10 · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

My cm871 doesn't kick fan in till 215. I have an override switch so I tend to use it before it gets there

Evotrucker · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

(05-08-2019 )Chamberpains Wrote: Where is your laptop with Insite and inline adapter. Please oh please don't tell me after all we've seen you do to this truck, and you don't have Insite?

If you do, go to data monitor\logger and check your fan control switch. Is it being commanded on? In ECM Diagnostic Tests you can perform a switch test. Toggle your fan on and off to see if its engaging or leaking air.
Your problem may just be the solenoid isn't allowing it to come on or your clutch in the hub is shot. Does it engage when you turn the key off and disengage when you key on?

Hey mr chambers! Thanks for telling me ahead of time on what to do!. I just got home n I got 2 hours to spare before running back n doing the same run I did yesterday. So I literally just hooked everything up n ran the “ fan over ride test “. I did a 1 minute test and then a 2 minutes test. It kicked on and worked just fine.

While I was at it, I went to check if their were any new faults that I wasn’t aware of n found 2 new ones.

Evotrucker · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

(05-08-2019 )Lonestar10 Wrote: My cm871 doesn't kick fan in till 215. I have an override switch so I tend to use it before it gets there

How hard is it to install one of those switches in a Volvo?

Rawze · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

(05-08-2019 )Evotrucker Wrote:
(05-08-2019 )Lonestar10 Wrote: My cm871 doesn't kick fan in till 215. I have an override switch so I tend to use it before it gets there

How hard is it to install one of those switches in a Volvo?

many people just buy a second fan solenoid and plumb it into the air feed hose for the clutch, wire it to +12v fused, key-on-only circuit into the dash. No special programming or ECM codes to worry about.

Lonestar10 · 05-08-2019, **(Subject: Cm870 overheating issue? Maybe )**

What he said mine is an oem switch from the factory